Update README

README.md

@@ -1,18 +1,151 @@
 # Pandoc
 
-**TODO: Add description**
+A watcher and a Mix task that uses Pandoc to convert markdown files to html.
+
+## Requirements
+
+- inotify-tools
+- pandoc
 
 ## Installation
 
-If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `pandoc` to your list of dependencies in `mix.exs`:
-
 ```elixir
+# mix.exs
+
 def deps do
   [
-    {:pandoc, "~> 0.1.0"}
+    {:pandoc, "~> 0.1.0", runtime: Mix.env() == :dev}
   ]
 end
+
+defp aliases do
+  [
+    # ...
+    "documents.build": ["pandoc hello"],
+    "statics.build": ["assets.build", "documents.build"],
+    "statics.deploy": ["assets.deploy", "documents.build"]
+  ]
+end
+```
+
+```elixir
+# config/config.exs
+
+config :pandoc,
+  hello: [
+    args: ~w(--mathjax -o ../priv/static/posts),
+    cd: Path.expand("../documents", __DIR__)
+  ]
+```
+
+```elixir
+# config/dev.exs
+
+config :hello, HelloWeb.Endpoint,
+  # ...
+  watchers: [
+    # ...
+    pandoc: {Pandoc, :run, [:hello, ~w(--watch)]}
+  ]
+
+config :pandoc, hello: [pattern: "**/*.md"]
+```
+
+```elixir
+# lib/hello_web/router.ex
+
+  scope "/", HelloWeb do
+    pipe_through :browser
+
+    get "/drafts/:id", PostController, :draft
+    get "/posts/:id", PostController, :show
+    get "/posts", PostController, :index
+
+    get "/", PageController, :home
+  end
+```
+
+```elixir
+# lib/hello_web/controllers/posts_controller.ex
+
+defmodule HelloWeb.PostController do
+  use HelloWeb, :controller
+
+  alias Hello.Document
+  @path "documents/**/*.md"
+  paths = Path.wildcard(@path)
+  @paths_hash :erlang.md5(paths)
+  for path <- paths, do: @external_resource(path)
+  @posts Document.list()
+
+  def __mix_recompile__?(), do: @path |> Path.wildcard() |> :erlang.md5() != @paths_hash
+
+  def index(conn, _params) do
+    render(conn, :index, posts: @posts)
+  end
+
+  def show(conn, %{"id" => id}) do
+    assigns = [
+      post: :hello |> :code.priv_dir() |> Path.join("static/posts/#{id}.html") |> File.read!()
+    ]
+
+    render(conn, :show, assigns)
+  end
+
+  def drafts(conn, %{"id" => id}) do
+    config = Application.get_env(:pandoc, :hello)
+
+    opts = [
+      cd: config[:cd] || File.cwd!()
+    ]
+
+    filename = List.keyfind(@posts, id, 0) |> elem(1) |> Map.get(:filename)
+    path = Path.join("_drafts", filename)
+
+    render(conn, :show, post: "pandoc" |> System.cmd([path], opts) |> elem(0))
+  end
+```
+
+```elixir
+# lib/hello/document.ex
+
+defmodule Stasis.Document do
+  require Logger
+
+  @ext ".md"
+  @pattern Application.compile_env(:pandoc, [:hello, :pattern])
+
+  def list() do
+    "documents"
+    |> Path.join(@pattern)
+    |> Path.wildcard()
+    |> Enum.map(fn path -> {Path.basename(path), path} end)
+    |> Enum.sort(fn {basename_a, _}, {basename_b, _} -> basename_a < basename_b end)
+    |> Enum.reduce([], fn {filename, path}, acc ->
+      id = Path.rootname(filename, @ext)
+      data = if "_drafts" in Path.split(path), do: %{:draft, true}, else: %{}
+
+      [{id, data} | acc]
+    end)
+  end
+```
+
+```elixir
+# lib/hello_web/controllers/post_html/index.html.heex
+
+<%= for {id, data} <- @posts do %>
+  <p>
+    <.link href={href(Path.rootname(filename), data[:draft])} method="get">
+      <%= id %>
+    </.link>
+  </p>
+<% end %>
+```
+
+```elixir
+# lib/hello_web/controllers/post_html/show.html.heex
+
+<%= raw(@post) %>
 ```
 
 Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)